Notching and “Removal” - Began Late August 2012
Although this initial task takes top billing in news reports and press releases, removal of the dam is just the first step in the restoration of this stretch of the Olentangy River. Plans call for only a partial removal of the dam in the center of the river channel. Portions of the dam at each shoreline will remain in place and will form the foundation for newly constructed riverbanks. Initially, a 3.5-foot deep notch will be made in the dam to allow water to release from impoundment over a period of a few days. Once the water levels drop in response to the initial notching, the center portion of the dam will be removed down to the concrete dam foundation. The foundation of the dam will also remain in place and will not be removed.
River Feature Reconstruction – Fall 2012
After water levels are lowered by removing the center portion of the 5th Avenue Dam, the shoreline areas will be prepared for planting. Invasive plants that currently grow on the riverbanks will be removed, and the eastern and western shorelines will be “sculpted” into new riverbanks. More than 20 storm sewer outfalls that flowed into the river will be reconstructed as “scour pools” to reconnect them to the location of the new shorelines. Four new wetlands will be constructed, with three wetland areas planned along the western bank of he Olentangy River, and one more wetland along the eastern bank near Woody Hayes Drive. Other river features such as pools (areas of deeper water) and riffles will be constructed throughout the river from Lane Avenue to Fifth Avenue.
Riverside Planting – Spring 2013
Newly “sculpted” riverbanks will be planted with vegetation to hold soil in place and create riparian habitat along each shoreline. Vegetation was selected based on its intended location, with plants that thrive in wet areas to be planted closest to the river's edge. Further up the bank, trees and shrubs will be planted to provide a more natural riparian habitat. Trees planted along the highest edges of the river shoreline will eventually provide shade that helps to regulate water temperatures in the river. At the four areas where wetlands will be constructed, suitable wetland plants were selected.
See project rendering (large file)
See projected views for completion, 5 years and 25 years after completion
See drawings of the existing & proposed river